Hello Again Alexandria,
Thank you for the the 'Towsure' output detail.
The bit that seems to be causing some minor concern is this:
"Achievable Noseweight 6%
Although the towcar has a potential noseweight of 90kg, that is within or greater than the target noseweight (62 - 88kg), however the actual hitch limit of the caravan is only 75kg. This combination is therefore constrained by the hitch limit set by the caravan manufacturer. Always check the noseweight of your caravan/payload before purchase and when loading."
First let me reaffirm providing you are not currently over loading the hitch there is nothing to be unduly concerned about, provide the van is towing well.
The possible issue seems to be the Towsure data has the caravan manufacture setting a maximum permitted nose load of only 75kg. This is unusually low, as most caravan chassis are usually rated for a maximum nose load of 100kg - You should find the maximum permitted nose load (S Value) on the caravan chassis data plate, usually near or on the hitch assembly.
The danger is, Firtsly it is technically illegal to exceed a nose load limit (though some will tell you the authorities never check nose load) so it is important that you do ensure you keep the static nose load less than lowest limit of either the trailer (75kg?) or the car manufacturer.
Why "static"? well its the only way you can actually measure the nose load when the outfit is stationary. In practice when you tow the vibrations and changes of direction will cause the dynamic load to be several times bigger than the static loads, but this will have been fully taken into account by the car and caravan manufacturers in their design and testing stages. Just a note it is perfectly safe to leave the caravan hitched to the car at home or at the services and move around inside the caravan fixing a drink or a meal.
Mechanically if it is over loaded when towing, it may prevent the trailer brakes from operating. It could also over stress some of the caravans components causing damage to either the car or caravan.
Measuring nose load is extra critical, if you are working close to its permitted limits, and measuring it incorrectly will give you a false reading. Something that is not always obvious is if caravan hitch is measured at the wrong height it will give wrong nose load readings, which is why the regulations require the nose load to be measured with the trailer hitch at the same height was when it is coupled to the tow vehicle, and that should be between 350 and 420mm from the ground to the centre of the tow ball
Unless you have access to a weighbridge that can measure individual axle loads, the only practical way to measure with a reasonable degree of accuracy and certainty is as follows:
You will need a piece of horizontal (no slopes of any kind), a set of bathroom scales, the caravan's portable step, some magazines to pack under the scales, and a poly bag to put over the caravan hitch to protect the scales from grease.
Load the car and caravan as if you are about to set off on your journey will all luggage and people. Pull forward on to a piece of horizontal ground, and measure the height of the underside of the coupled tow hitch from the ground.
Chock the caravan wheels, DO not use the caravans hand brake and uncouple it from the car.
Put the scales on the step and pack them up using the magazines so the top of the scales is the same as the measured height of the hitch. Put the bag over the hitch, and lower it onto the scales making sure that none of the caravans steadies or the jockey wheel are in contact with the ground.
The displayed reading will be the nose load.
Sadly No one, including your weightlifting partner, can be consistently accurate about assessing the weight of an object just by lifting it, so don't chance it.